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Revs Dropping rather Low
Posted: Tue Jan 29, 2013 1:01 pm
by prelude_h22
HI All
just a quick question
Ive noticed that when i drive in traffic the revs seem to drop rather low after i brake - it doesnt stall but it feels like it almost does.
Also when i am stationary and i pump the brake rapidly it drops rather low too. it doesnt stall though
Is this normal for a H22?
everything else seems fine. it drives fine and idles fine
PS - whats the normal revs for H22 idle?
cheers peeps
Posted: Tue Jan 29, 2013 1:05 pm
by Gayno
Mine did this last year, even the pumping brake pedal bit.
But can I remember what I did to fix it? Can I hell!!
I think it was the coolant, so you might want to check the level and bleed the system.
Posted: Tue Jan 29, 2013 1:05 pm
by bennyboy
prelude_h22 wrote:
PS - whats the normal revs for H22 idle?
cheers peeps
Mine was always about 780-800
Posted: Tue Jan 29, 2013 1:40 pm
by Gayno
bennyboy wrote:prelude_h22 wrote:
PS - whats the normal revs for H22 idle?
cheers peeps
Mine was always about 780-800
REMEMBERED!
All I did was lower my idle using the base idle screw on the throttle body. Only slightly, but it was enough to stop the above from happening!
Posted: Tue Jan 29, 2013 1:42 pm
by Supermarine Blues
I think it's actually the IACV that needs cleaning. Or replacing or something.
Posted: Tue Jan 29, 2013 1:51 pm
by Merlin
Usually IACV faults cause the engine to idle at a higher RPM, or bounce.
I once had a rev dropping issue when pulling up at juctions etc.. Turned out I had a hole in my exhaust before the O2 sensor.
Posted: Tue Jan 29, 2013 1:54 pm
by Donald
Mine seems to intermittently do this low revs thing. Only very slightly but it's not consistent, sometimes it'll be at a junction, sometimes it just be without driving anywhere but up to running temp. Sometimes it'll be doing it at a junction, I'll creep forward and then stop again, and the idle is then normal.
Posted: Tue Jan 29, 2013 2:07 pm
by BMCC
When you pump the brake pedal does the idle bounce up higher or does it just gradually creep back to normal?
Part of the Idle control is taken from the brake switch. When you brake your taking air out of the inlet and using this to boost your braking. The idle control should get a signal from the switch and open up the IAC to get more air in to compensate. Try cleaning the brake switch and see if that helps, although you might need to see if the ECU is getting an appropriate voltage when the brakes are pressed. (see the manual for this)
Posted: Tue Jan 29, 2013 2:12 pm
by Shiny
I have had similar problems in the past on other Hondas.
One was initially down to lambda sensor, later down to head gasket.
The other was either the ICM or Coil, i ended up replacing both. Got the point where it would almost cut out completely when braking at a junction.
Had a similar thing on the ATR, Rich @ PA put this right with an adjustment to idle screw thingy.
Posted: Tue Jan 29, 2013 6:13 pm
by prelude_h22
REMEMBERED!
All I did was lower my idle using the base idle screw on the throttle body. Only slightly, but it was enough to stop the above from happening!
CHeers Gayno - i might try this. Where abouts is the base idle screw located?
Usually IACV faults cause the engine to idle at a higher RPM, or bounce.
I once had a rev dropping issue when pulling up at juctions etc.. Turned out I had a hole in my exhaust before the O2 sensor.
I think it's actually the IACV that needs cleaning. Or replacing or something
I might try cleaning it anyways - where is the IACV located?
When you pump the brake pedal does the idle bounce up higher or does it just gradually creep back to normal?
Part of the Idle control is taken from the brake switch. When you brake your taking air out of the inlet and using this to boost your braking. The idle control should get a signal from the switch and open up the IAC to get more air in to compensate. Try cleaning the brake switch and see if that helps, although you might need to see if the ECU is getting an appropriate voltage when the brakes are pressed. (see the manual for this)
Yeah the ilde bounces higher when i pump the brake peadal. When i stop pumping the brake the revs drop and it feels it wants to stall. Ill have a diagnosis session on this when the weather gets warmer
I have had similar problems in the past on other Hondas.
One was initially down to lambda sensor, later down to head gasket.
The other was either the ICM or Coil, i ended up replacing both. Got the point where it would almost cut out completely when braking at a junction.
Had a similar thing on the ATR, Rich @ PA put this right with an adjustment to idle screw thingy.
Cheers Shiny.
It seems like the idle screw is a good place to start
cheers guys